Disaster evolution mechanism of surrounding rock structure of deep roadway based on multi⁃source information representation

As the intensity and depth of deep coal mining continue to increase，the disaster caused by the structural in⁃ stability of deep roadway surrounding rock becomes increasingly severe and complex，which seriously restricts the safe and efficient mining of deep coal resources. To investigate the multiple physical response information of deep roadway surrounding rock in the gradual evolution of deformation and instability， a self⁃developed simulation system for the complete process of deformation and instability of deep underground engineering structure was used，with the acoustic emission，parallel electrical method，electromagnetic radiation monitoring system，to carry out the destructive physical model tests of intact，layered and massive surrounding rock structures. The whole process of load⁃displacement of surrounding rock with different structures was quantitatively analyzed and characterized based on the evolution law of acoustic emission，apparent resistivity and electromagnetic radiation multi⁃source information. The disaster evolution and instability mechanisms of surrounding rocks with different structures were comprehensively revealed from the per⁃ spectives of load⁃displacement curve，multi⁃source information response law and post⁃peak damage characteristics of surrounding rocks. The results show that 1 With the decrease of rock structural integrity，the roadway surrounding rock changes from plastic failure to brittle failure，and its deformation and failure process is characterized by volatility and progressive failure. Compared with the intact structure，the equivalent peak bearing capacities of layered and mas⁃ sive surrounding rocks decrease by 4. 73% and 20. 73%， respectively. 2 Different from the continuous response process of the acoustic emission，apparent resistivity and electromagnetic radiation multi⁃source information of the intact structure surrounding rock，the layered and massive structure surrounding rocks show the phase response law， and the characteristic value is more prominent，showing the phase jump law. 3 The areas of fracture zones in intact， layered and massive structures are 448.84，651.76 and 824.49 cm2，respectively. With the decrease of the structural integrity of surrounding rock，the area of fracture zones increases continuously，ranging from 1.5 to 1.9 times in this study. 4 The instability mechanism of surrounding rock changes from the strength control type of intact structure to the structure control type of massive structure，while the layered structure shows the characteristics of com⁃ bined strength and structure control. And the structural effect of surrounding rock failure and instability is becom⁃ ing more and more significant.